Transaction history in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a transaction history in system design?

Transaction history is a record of all actions or changes made to data over time, allowing tracking and auditing of past operations.

intermediate

Why is immutability important in transaction history design?

Immutability ensures that once a transaction is recorded, it cannot be changed or deleted, preserving data integrity and auditability.

beginner

Name two common storage options for transaction history data.

1. Append-only logs or event stores 2. Relational databases with audit tables

intermediate

What is the role of indexing in transaction history systems?

Indexing helps quickly retrieve transaction records by attributes like user ID, date, or transaction type, improving query performance.

beginner

How does pagination help in displaying transaction history?

Pagination breaks large transaction lists into smaller pages, making it easier to load and view data without overwhelming the system or user.

What is the main purpose of maintaining a transaction history?

A To track and audit all changes over time

B To delete old data automatically

C To speed up data entry

D To encrypt user passwords

Transaction history records all changes to enable tracking and auditing.

Which storage type is best suited for immutable transaction records?

A Session storage

B Temporary cache

C In-memory database

D Append-only log

Append-only logs store immutable records by only adding new entries.

Why is indexing important in transaction history systems?

A To encrypt data

B To improve query speed

C To delete old transactions

D To compress data

Indexing speeds up searching and retrieving transaction records.

What does pagination help with when showing transaction history?

A Breaking data into manageable pages

B Encrypting transaction data

C Deleting duplicate records

D Backing up data

Pagination divides large data sets into smaller pages for easier viewing.

Which property ensures transaction history cannot be altered after recording?

A Compression

B Encryption

C Immutability

D Caching

Immutability means data cannot be changed once recorded.

Explain the key design considerations when building a transaction history system.

Think about how to keep records safe, easy to find, and easy to view.

Describe how transaction history supports auditing and troubleshooting in applications.

Consider why knowing past actions is important for fixing problems and following rules.